1. Field of the Invention
The present invention relates to an exercise machine, and more particularly to a modular unit attachable to and usable with a preexisting weight training machine. The modular unit is adapted to enable certain compound motions generally not possible with standard weight and pulley exercise machines.
2. Description of the Prior Art
Exercising machines employing suspended weights for providing a resistance to body motions are well known in the prior art. These machines generally include a frame supporting weights attached to a tether. The tether is connected, in turn, to levers and similar components which are grasped by a user and manipulated. Manipulation against the resistance of the weights forces muscles to exert great effort, and thus will increase the strength or bulk of the muscles, or both, over time.
However, compound motions are seldom provided for in weight machines. Such motions are desirable since they can parallel natural body movement, and enable exercising muscles and groups of muscles that frequently cannot be properly exercised by simple motions. The reason why these motions tend to be ignored is that they frequently require great complexity of the machine. For example, a lever may require pivoting about plural axes. A compound motion may require substantial linear movement followed by a rotating movement. Any combination of these and other motions may be required, and may be further complicated by the requirement for gradual transition from one motion to the next.
U.S. Pat. No. 5,273,509, issued to Larry W. Vittone on Dec. 28, 1993, discloses a handle for a weight machine wherein right and left arms are each provided with an independently pivotable handle. Each handle is provided with a pivot comprising a ball joint located close to, but spaced apart from, the other ball joint. The two handles can pivot independently of one another. The motion so provided accommodates motion of each hand through a curved plane defined at a fixed radius from the center of the ball of the ball joint, and constrained by the maximum travel of the lever within the socket of the ball joint.
This device requires two joints, one for the handle for each hand. The nature of the device requires careful and precise fabrication, since the amount and constancy of frictional resistance of movement of the ball within the socket is subject to change over time and with wear. Extremely minute adjustments to the tightness of the socket components will greatly affect frictional resistance. It is therefore believed by the applicant that reliance upon ball joints renders the device most difficult to adjust with respect to intentionally varying this resistance. Also, wear and contamination may require frequent adjustment merely to maintain a constant degree of resistance.
A two armed exercising apparatus is shown in U.S. Pat. No. 2,529,347, issued to Stanley R. Mohler et al. on Nov. 7, 1950. The arms form a vee, and are hinged at the center of the vee. The arms are extended so that the overall configuration is generally that of an "H". A spring disposed upon the extensions of the arms resists spreading of the arms. This apparatus lacks gearing provided in the present invention for assuring that the arms spread and converge to the same degree.
It is frequent practice to attach a two grip handle to the cable of a weight machine. This attachment enables a user to hold the bar at a comfortable location or position. However, it does not enable a user to change the relative positions of his or her right and left hands relative to one another.
One example of this type of invention will be described in further detail, although the reader is cautioned to recognize the limited relevance to the instant invention. U.S. Pat. No. 5,267,930, issued to Richard W. Henes on Dec. 7, 1993, describes a weight machine wherein a handle is attached to a cable which can be pulled forwardly of the machine. The nature of the attachment enables the handle to pivot nearly universally with respect to the cable, and therefore to the machine. The handle comprises a single rod bent to enable right and left hand grips to project from the rod at an angle. This provides more comfortable grip. However, both handles are fixed on the rod, and no exercise can be performed wherein the user's arms approach one another.
The same feature regarding mounting of a solid exercise bar or the like is seen in U.S. Pat. Nos. 3,640,528, issued to Richard Proctor on Feb. 8, 1972; U.S. Pat. No. 3,850,431, issued to Louis A. Winans on Nov. 26, 1974; U.S. Pat. No. 4,441,706, issued to Mark M. Korzaniewski on Apr. 10, 1984; U.S. Pat. No. 4,564,194, issued to Fred Dawson on Jan. 14, 1986; U.S. Pat. No. 4,744,559, issued to Parker E. Mahnke et al. on May 17, 1988; U.S. Pat. No. 4,986,538, issued to Arthur B. Ish III on Jan. 22, 1991; U.S. Pat. No. 5,184,992, issued to Gary S. Banks on Feb. 9, 1993; and U.S. Pat. No. 5,273,506, issued to Frederic O. Dawson, Jr. on Dec. 28, 1993.
In these listed examples, a simple pulling exercise is enabled, and the user's arms and hands are constrained to relatively unvarying positions. There is no means for preventing unbalancing of the apparatus should the bar of one arm be moved more than the other, as may occur if one arm is stronger than the other, or if the user subconsciously exerts more force with one arm.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.